1. Field of the Invention
The present invention relates to a floppy disk apparatus for recording and reproducing a floppy disk having a diameter of, for example, 3.5 inch or the like.
2. Description of Related Art
As shown by FIG. 1 and FIG. 2, a floppy disk apparatus 1 is for recording and reproducing a floppy disk 2 comprising a magnetic disk having a diameter of 3.5 inch or the like and the floppy disk 2 is used by being contained rotatably in a flat disk cartridge 3. Further, the disk cartridge 3 is formed with a pair of upper and lower head insertion holes 3a and attached with shutters (not illustrated) for opening and closing the head insertion holes 3a.
Further, the floppy disk apparatus 1 is formed in a shape of a flat box by three exterior members of a chassis 4 formed by aluminum die casting or sheet drawing, a cover 5 formed by drawing a thin plate and attached above the chassis 4 and a front panel 6 formed by synthetic resin and attached to front ends of the chassis 4 and the cover 5. Further, a cartridge insertion port 6a is formed at the front panel 6 and a main printed substrate 7 is screwed to a lower face of the chassis 4.
Further, at inside of the floppy disk apparatus 1 and above the chassis 4, a cartridge holder 9 is arranged horizontally, and the cartridge holder 9 is attached above the chassis 4 such that the cartridge holder 9 is capable of freely elevating and lowering in the up and down direction by a parallel motion by a holder elevating and lowering mechanism 10 having slide plates 10a having a sectional shape of a substantially a channel-like shape and directed upwardly which is conventionally and publicly known. Further, a shutter opening and closing lever 9a is attached to a rear end of the cartridge holder 9 and an eject button 10b attached to front ends of the slide plates 10a is projected forward from the front panel 6.
Further, on a center line P at inside of the floppy disk apparatus 1 and at a lower position of the cartridge holder 9, a spindle motor 11 which is a direct current motor attached horizontally to the chassis 5 is arranged and a disk table 12 is horizontally fixed to an upper end of a vertical spindle 11a of the spindle motor 11. Further, at inside of the floppy disk apparatus 1 and at a rear position of the disk table 12, a head mechanism 14 attached on the chassis 4 is arranged.
The head mechanism 14 is constituted by a head carriage 15, a head arm 17 attached rotatably in the up and down direction via a leaf spring 16 or the like above the head carriage 15, a pair of upper and lower magnetic heads 18a and 18b attached opposedly in the up and down direction on upper and lower opposed faces at front ends of the head carriage 15 on the head arm 17 via cymbal plates (not illustrated), a stepping motor 19 which is a motor for moving the head, a horizontal lead screw 20 directly connected to a motor shaft 19a of the motor, a horizontal guide shaft 21 in parallel with the lead screw 20 and so on. Further, the pair of upper and lower magnetic heads 18a and 18b are arranged on the center line P which is on a radial line from the center of the floppy disk 2.
Further, a needle 15a formed at one side portion of the head carriage 15 is engaged with the lead screw 20, and a thrust bearing 15b integrally formed with other end portion of the head carriage 15 is inserted slidably on the outer periphery of the guiding shaft 21. Further, the magnetic head 18a on the upper side is inserted into a notch 22 formed at a central portion on a rear end side of the cartridge holder 9 and a guided projection 17a integrally formed with one side face of the head arm 17, is brought into slidable contact with a guide rail 9b formed at one side edge of the notch 22 of the cartridge holder 9. A head moving mechanism 34 is constituted by the stepping motor 19, the lead screw 20, the guide shaft 21 and so on mentioned above.
Further, according to the conventional floppy disk apparatus 1, when the disk cartridge 3 is horizontally inserted in an arrow mark "a" direction from the cartridge insertion port 6a into the cartridge holder 9, shutters of the disk cartridge 3 are opened by the shutter opening and closing lever 23 and the slide plates 10a of the holder elevating and lowering mechanism 10 are slid in an arrow mark "b" direction and the cartridge holder 9 is lowered in a horizontal state. Further, the disk cartridge 3 is lowered in a horizontal state, the floppy disk 2 at inside thereof is chucked to the spindle 11a and the disk table 12 from above by a center core 2a and the pair of upper and lower magnetic heads 18a and 18b are inserted from the pair of upper and lower head insertion holes 3a formed at the disk cartridge 3 into the disk cartridge 3 and are brought into light press contact with both upper and lower faces of the floppy disk 2. Further, in the state of chucking the floppy disk 2, the guide rail 9b of the cartridge holder 9 is lowered below the guided projection 17a of the head arm 17.
Further, the floppy disk 2 is driven to rotate by the spindle motor 11 and the head carriage 15 and the head arm 17 are integrally moved in the arrow mark "a" or "b" direction by the lead screw 20 driven to rotate by the stepping motor 19 while guiding the head carriage 15 by the guide shaft 21, by which the pair of upper and lower magnetic heads 18a and 18b are moved along the center line P in the arrow mark "a" or "b" direction and recording and reproducing of both upper and lower faces of the floppy disk 2 are carried out by the pair of upper and lower magnetic heads 18a and 18b.
Further, after recording or reproducing operation, when the eject button 10b is pushed in the arrow mark "a" direction, the slide plates 10a of the cartridge elevating and lowering mechanism 10 are slid in the arrow mark "a" direction and the cartridge holder 9 is elevated in a horizontal state. Further, the disk cartridge 3 is elevated in a horizontal state and the floppy disk 2 at inside thereof is detached upward from the spindle 111 and the disk table 12 and the pair of upper and lower magnetic heads 18a and 18b are detached upward and downward from the disk cartridge 3 and thereafter, the disk cartridge 3 is ejected in the arrow mark "b" direction from the cartridge insertion hole 7a of the front panel 7 by the shutter opening and closing lever 9a.
However, according to the conventional floppy disk apparatus 1, after carrying out recording or reproducing operation of the floppy disk 2, when the floppy disk 2 is left for a long period of time while being chucked on the disk table 12, the pair of upper and lower magnetic heads 18a and 18b are left for a long period of time while being brought into light press contact with both upper and lower faces of the floppy disk 12 and depending on environment of high temperature, high humidity or the like, the pair of upper and lower magnetic heads 18a and 18b may be pasted on both upper and lower faces of the floppy disk 2 as they are. Further, when the spindle motor 11 is unpreparedly started or the floppy disk 2 is unpreparedly ejected without knowing the pasted state of the pair of upper and lower magnetic heads 18a and 18b, support parts of cymbal plates or the like supporting the pair of upper and lower magnetic heads 18a and 18b or the floppy disk 2 per se are liable to destruct.